1. Field of the Invention
The invention relates to a rotary leadthrough of a robot arm, in particular of a fourth axle of a Delta robot.
2. Prior Art
Delta robots are known from European Patent Disclosures EP-B 0 250 470, EP-A 1 129 829, and EP-A 1 293 691. These Delta robots are suitable for moving objects precisely and in a guided way in three-dimensional space. They have proven themselves in practice and are used, among other fields, in the food industry or in machining centers that have stringent cleanliness requirements. Cleaning the rotary leadthrough of the fourth axle, however, is sometimes complicated. Until now, this rotary leadthrough has been embodied such that a hollow shaft was supported in a housing, and the shaft had a radial inflation opening in its central void.
Precisely in the aforementioned areas of use, however, it would be desirable to be able to clean the entire robot and especially the region of the rotary leadthrough of the fourth axle better and more simply.
U.S. Pat. No. 5,775,169 moreover discloses a robot arm that is used for manipulation in a vacuum chamber, but that is operated from outside. The robot arm is rotatably supported in a housing, and there is a seal in the housing, for dividing the part of the robot arm toward the vacuum from the part toward the atmosphere.
It is therefore an object of the invention to create a rotary leadthrough for a robot arm, in particular for a fourth axle of a Delta robot, which is constructed simply and is less vulnerable to soiling and which makes good cleaning possible.